This invention relates to a system for the stable running of a marine propulsion unit and more particularly to an improved arrangement for preventing unwanted watercraft action upon the popping up of an outboard drive due to its striking an underwater obstacle or under similar circumstances.
As is well known, most outboard drive units, either outboard motors or the outboard drive portion of an inboard/outboard drive, are supported for pivotal movement about a horizontally extending tilt axis. This tilting movement is provided for a variety of reasons such as to adjust the trim angle, to permit the outboard drive to be tilted up when not in use and also so as to permit popping up of the outboard drive when an underwater obstacle is struck. This latter purpose is intended to prevent damage to the outboard drive under this type of condition.
Although permitting popping up of the outboard drive when an underwater obstacle is struck protects the outboard drive; when the outboard drive returns to its normal running position, there can be certain unsatisfactory conditions arise in the resulting watercraft. For example, the rapid change of trim can produce a surging in the condition in the watercraft that can upset the passengers, it can cause a rolling operation of the watercraft or it could result in an abrupt and unexpected turn in the watercraft direction. Although these conditions are less objectionable than those which would result if popping up were not permitted, it would be desirable if they could also be avoided.
It is, therefore, a principal object of this invention to provide an arrangement for providing stable running when the outboard drive has popped up and returned to its normal running condition.
It is a further object of this invention to provide an arrangement for achieving stability under popping up operation by slowing the speed of the propulsion unit for a time period after the outboard drive returns to its normal position.